End use will always influence the type of Masterbatch chosen. Toys and food packaging
for example have to be produced from materials made
with 'controlled' ingredients and engineering products will demand reliable high
performance properties. Typically, an off-the-shelf Masterbatch
formulation, chosen for colour but incorporating premium priced additives for high specification polymers,
when used in an 'uncontrolled' application in a low temperature commodity polymer,
would be grossly over-engineered and unnecessarily expensive.
Other typical determining factors might be service conditions such as weatherability or light fastness, for example.
How Masterbatch is made
In simple terms, manufacture is a two-stage process: gathering ingredients and then mixing them together
by applying heat and shear to produce an homogenized pellet. Generally high or low speed
mixers are used to produce a pre-mix of the additives which is then compounded on roller mills, kneaders, single or twin screw extruders.
Even distribution (dispersion) and development (breaking down) of the additives throughout the carrier are essential.
This processing depends on several key elements: formulation, quality of raw materials, quality of mixing and
compounding plant. Finally, the finished Masterbatch is palletised (die-face) not ground.
Using our Masterbatch
Masterbatch can be introduced to the processors' base polymer on the production line in a number of ways,
the most successful methods being volumetric or gravimetric dosing.
In both techniques, the Masterbatch is added directly into the polymer stream immediately before processing.
Volumetric dosing has the advantage of relatively low capital investment
but requires calibrating every time the batch or colour is changed (depending on the bulk density of the material).
Gravimetric dosing is extremely accurate.
Wall thickness and opacity requirements all affect dosage. Although influenced by homogenisation and dosage level,
getting the loading right for the production of transparent colours is particularly tricky, as any imperfection is clearly visible.
Sometimes it is useful to go for a weaker Masterbatch so the demands
on homogenisation and dosage are reduced.
Our Masterbatch may be stored for up to five years ensuring that it is kept Dry and at stable Temperature.
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